fix(ListBox): Fix various toolbar button states

Author: theOrlin

styles/web/type-flat.less

@@ -2787,6 +2787,12 @@ html .km-pane-wrapper .km-widget,
         color: @input-text-color;
     }
 
+    .k-button.k-state-disabled{
+        .k-icon {
+            color: @disabled-text-color;
+        }
+    }
+
     .k-drop-hint {
         height: 0;
         border-top: 1px solid @accent;

styles/web/type-material.less

@@ -4193,6 +4193,13 @@ div.k-scheduler-marquee:after {
         }
     }
 
+    .k-button.k-state-disabled:hover
+    {
+        .k-icon {
+            opacity: .7;
+        }
+    }
+
     .k-drop-hint {
         height: 0;
         border-top: 1px solid @accent;

styles/web/type-nova.less

@@ -2495,6 +2495,10 @@ html .km-pane-wrapper .km-widget,
         opacity: .2;
     }
 
+    .k-button.k-state-disabled:active .k-icon {
+        opacity: .2;
+    }
+
     .k-drop-hint {
         height: 0;
         border-top: 1px solid @accent;